With the increasing use of electronic communications the use of encryption technology has become commonplace, with a trust authority being responsible for issuing decryption keys, thereby allowing the secure exchange of electronic data.
However, some users of encryption systems have concerns that using a single trust authority to provide a decryption key creates a point of compromise or system failure.
To overcome this problem multiple trust authority encryption systems have been proposed where typically two or more trust authorities act as cooperating parties, where a shared secret is held by all cooperating trust authorities. To ensure that no single trust authority can be a point of compromise or system failure none of the cooperating parties have sufficient information to be able to derive the shared secret independently.
However, this solution requires that all of the relevant trust authorities have to be involved in running such a secret sharing scheme and it may be difficult to organise the relevant trust authorities to run such a secret sharing protocol, since, for various reasons, some of them may not be interested in co-operating with the other trust authorities.
It is desirable to improve this situation.